Syringe assembly



Nov. 12, 1957 s. w. FERGUSON 2,312,763

' SYRINGE ASSEMBLY Original Filed March 8, 1954 INVENTO R fiarwoaifii'gasarv ATTORNEYS United States Patent SYRINGE ASSEMBLY ApplicationJuly 17, 1956, Serial No; 598,729

1 Claim. (Cl. 128-218 This invention relates to a structurally andfunctionally improved hypodermic syringe assembly; the presentapplication being a substitute for my prior application for UnitedStates Letters Patent Serial No. 414,807, filed March 8, 1954, andidentified under Syringe Assembly, now abandoned.

It is an object of the invention to furnish a structure of thischaracter which may be either repeatedly used or else subjected to aone-time use, after which it is discarded. When so employed, it may befilled with medicament which will be maintained in stable condition freefrom contaminating factors for indefinite periods of time. However, theunit may be instantly rendered available for use when this becomesnecessary.

A further object is that of furnishing a syringe to which a standardneedle may readily be fitted and which syringe will be ideally adaptedfor placement in a kit such as is employed in the Armed Services, theassembly including relatively few parts, each individually simple inconstruction and capable of manufacture by inexpensive quantityproduction methods.

With these and other objects in mind, reference is had to the attachedsheet of drawings illustrating one practical embodiment of theinvention, and in which:

Fig. l is a rear view of the syringe assembly;

Fig. 2 is a side elevation thereof, and

Fig. 3 is a sectional side view taken along the line 3-3 in thedirection of the arrows as indicated in Fig. 1.

In these views the numeral 5 indicates the syringe barrel which, inaccordance with conventional practice, may be formed with a flange 6adjacent its rear or open end and provided with an end wall 7 on itsopposite end. All parts of this unit are preferably constructed of aplastic such as natural polyethylene, although other substances may beemployed.

With a view to providing a mounting for a needle, the forward wall hasextending from its outer face a collar 8, the inner face of which isformed with a spiral groove 9 for cooperation with the extended edgeportions of a needle hub (not shown). This collar is concentricallydisposed with respect to a tip 10 which also extends forwardly of endwall 7 to a point preferably beyond the edge of collar 3. This nozzle isformed with a bore 11 and is tapered throughout its length to provide asurface properly cooperable with the bore of the needle hub to establisha seat for and seal with the latter. The tip or nozzle 10 being alsopreferably formed of polyethylene an inherent resiliency and flexibilitywill be incorporated in this part such that it will--underpressure--conform to the adjacent needle hub surfaces.

Cooperating with barrel 5 is a plunger. That plunger may again be formedof a number of different materials. Preferably, however, it will includea body 12 formed of natural or synthetic rubber. It also includes anenlarged head or actuating portion 13 adjacent its rear end and aforward or piston portion 14 adjacent its forward end. Thediameter ofthe latter should be slightly larger than apparent that a proper sealwill be established between this piston portion and the bore face of thebarrel. Such a seal will, of course, also be assured if the dimensionsof the parts are generally proper and because of the comfortable natureof the materials of which these parts are formed. Body 12 is formed witha bore 15 extending through to its rear face. This bore terminates shortof the forward face of the enlarged or piston portion 14. Therefore, awall 16 exists at this point. That wall being formed of a materialhaving restoring tendencies it follows that if Wall 16 is pierced by acannula which is subsequently withdrawn, the structure will beself-sealing.

To normally maintain the forward end of the syringe in an ascepticcondition and guard the contained medicament against escape andcontamination, a cap is employed. This cap as shown may include a headportion 17, the outer edge of which is conveniently knurled. It alsoincludes a plug in the form of a sleeve 18 of relatively heavy gauge,the outer face of which is preferably threaded as at 19 to engage withthreads 9. The bore of this sleeve is tapered to conform to the taperingof tip 10. Centrally of its head, the cap embraces a taperedprotuberance 20. The end of the latter is suificiently reduced so thatit may enter bore 11 and establish a sealing contact with the edgedefining the outer part of this bore and the surfaces adjacent suchedge. The cap is preferably formed of the same material as the body 5.The length of skirt or plug 18 is such that, when seated, it preferablyclears the base of the recess defined between tip 10 and collar 3.Likewise, when fully projected, the inner face of the head portion 17may clear or contact the outer edge of collar 8. In this connection, itwill be understood, due to the wedging action of the parts as theycooperate a definite limit will be imposed upon the amount the stopperor sleeve parts 18 of the cap may be telescoped with respect to theadjacent parts associated with the barrel.

At the same time a proper sealing contact will under all circumstancesbe established because of the materials which will be employed andwhichas threads 9 and 19 are relatively turned towards a tighteningposition-will cause the sleeve to somewhat extend with respect to itshead portion 17. This will have the result that the protuberance orvalve body 29 will be forced into bore 11 to a maximum extent thusassuring a proper contact. That contact will inevitably result in aproper seal because of the support provided to the tip by the outer faceof the latter contacting the bore of sleeve 18. This will prevent anypossible loss of medicament at this point. A secondary seal will, ofcourse, be established between the bore of that sleeve and the outertapered face of the tip or nozzle 10. The threads will prevent anyaccidental detachment of the cap.

In use, it will be appreciated that all of the parts are cleaned andsterilized. The cap may now be mounted in sealing contact upon theforward end of the syringe; the plunger having been fully projected towhere: the forward face of its piston portion lies in contact with theinner face of walls 7. Now, by introducing a suitable filling needle orcannula into recess or socket 15, wall 16 may be penetrated. Thereupon,by forcing the desired medical solution through this needle the body 5of the syringe barrel will be filled with liquid to the desired extentas shown, for example, in Fig. 3. Under these circumstances piston 14will be forced rearwardly to the position also shown. The unit may nowbe stored for any desired period of time and in filled condition. Itwill be instantly ready for use by removing the cap, employing a sterileneedle and mounting the latter on the forward end of the syringe barrel.

Of course, other methods of filling the syringe may likewise be resortedto. Also, if the syringe is to be subjected to repeated use it isapparent that the same technigues as heretofore utilized in connectionwith the cleaning, sterilization and filling of glass syringes may beutilized. The device will be extremely compact and where used inprefilled condition will contain just the amount of medicament which isdesired.

Thus, among others, the several objects of the invention as specificallyaforenoted are achieved. Obviously numerous changes in construction andre-arrangements of the parts might be resorted to without departing fromthe spirit of the invention as defined by the claim.

' I claim:

A syringe assembly including in combination a barrel, an end wall forsaid barrel, a bored tip extending outwardly from said wall, a collaralso extending outwardly from said wall and concentrically disposed withrespect to said tip, a cap, a sleeve forming a part of said cap toreceive said tip within its bore and engage with the surface of thelatter the outer face of the tip, said collar and sleeve being formed ofdistortable material, said sleeve being of relatively heavy gaugewhereby it provides a support for said tip as said sleeve is introducedinto the space between the latter and said ,collar to assure a sealingcontact between said sleeve and tip, a head portion forming a part ofsaid cap and having a diameter larger than said sleeve to overlie theend of said collar with said cap in applied position, cooperatingthreads forming a part of said sleeve and collar and engaged with eachother, a protuberance extending inwardly from the head portion of saidcap and formed .ofisimilar material, said protuberance projecting intothe bore; of said tip to establish sealing contact therewith and theadjacent faces of said tip and the, bore of said sleeve. being taperedto provide mating engaging surfaces throughout substantially the entirelength of said tip.

References Cited in the file of this patent UNITED STATES. PATENTS2,341,102 Kansaki Feb. 8, 1944 2,677,374 Burnside May 4, 1954 2,767,710Blackman Oct.'23,, 1956

